누락된 썸네일 생성 기능 구현

src/routes/(fullscreen)/settings/thumbnails/service.ts

@@ -0,0 +1,61 @@
+import { limitFunction } from "p-limit";
+import { encryptData } from "$lib/modules/crypto";
+import { getFileCache, storeFileCache, downloadFile } from "$lib/modules/file";
+import { generateImageThumbnail, generateVideoThumbnail } from "$lib/modules/thumbnail";
+import type { FileThumbnailUploadRequest } from "$lib/server/schemas";
+
+export const requestFileDownload = async (
+  fileId: number,
+  fileEncryptedIv: string,
+  dataKey: CryptoKey,
+) => {
+  const cache = await getFileCache(fileId);
+  if (cache) return cache;
+
+  const fileBuffer = await downloadFile(fileId, fileEncryptedIv, dataKey);
+  storeFileCache(fileId, fileBuffer); // Intended
+  return fileBuffer;
+};
+
+export const generateThumbnail = limitFunction(
+  async (fileBuffer: ArrayBuffer, fileType: string) => {
+    let url;
+    try {
+      if (fileType.startsWith("image/")) {
+        url = URL.createObjectURL(new Blob([fileBuffer], { type: fileType }));
+        return await generateImageThumbnail(url);
+      } else if (fileType.startsWith("video/")) {
+        url = URL.createObjectURL(new Blob([fileBuffer], { type: fileType }));
+        return await generateVideoThumbnail(url);
+      }
+      return null;
+    } catch {
+      // TODO: Error handling
+      return null;
+    } finally {
+      if (url) {
+        URL.revokeObjectURL(url);
+      }
+    }
+  },
+  { concurrency: 4 },
+);
+
+export const requestThumbnailUpload = limitFunction(
+  async (fileId: number, thumbnail: ArrayBuffer, dataKey: CryptoKey, dataKeyVersion: Date) => {
+    const thumbnailEncrypted = await encryptData(thumbnail, dataKey);
+    const form = new FormData();
+    form.set(
+      "metadata",
+      JSON.stringify({
+        dekVersion: dataKeyVersion.toISOString(),
+        contentIv: thumbnailEncrypted.iv,
+      } satisfies FileThumbnailUploadRequest),
+    );
+    form.set("content", new Blob([thumbnailEncrypted.ciphertext]));
+
+    const res = await fetch(`/api/file/${fileId}/thumbnail/upload`, { method: "POST", body: form });
+    return res.ok;
+  },
+  { concurrency: 1 },
+);